The invention concerns the technical sector relating to inserting batched quantities of granular or powder products in containers therefore, in the field of automated packing processes.
As is known, in order to define a predetermined quantity of a substance the weight parameter or the volume parameter can be used, according to what is optimal for the specific situation.
In particular, the invention relates to an apparatus in which the granular or powder product is batched with reference to a volume thereof.
On Feb. 4, 2007, the same applicant filed an Italian application for a patent, no. BO2007A 000236, entitled: “A Method for Batching Powder and/or Granular Products internally of Container Elements and an Apparatus destined to Actuate the Method,” in which a technical solution is provided which includes an obturator arranged transversally with respect to a vertical channel, superiorly delimited by a gas-permeable wall and inferiorly opening into the container into which a batched quantity of product is to be deposited.
The obturator is axially mobile between an advanced position, in which it occludes the vertical channel, and a retracted position, in which it is free.
With the obturator in the advanced position, a batching chamber having a predetermined adjustable volume is defined in the vertical channel between the obturator and the wall, which chamber is in communication with the supply hopper of the product via a recess, provided for this purpose in the upper part of the obturator, and an inlet conduit, realized laterally of the vertical channel.
The combined action of a star valve which pushes the product into the introduction conduit and a source of depression which, via the gas-permeable wall, places the batching chamber under a depression, determines an inflow of product into the chamber up until it is completely full.
A following retraction of the obturator, actuated in phase relation with the switching between the aspirating action produced by the depression source to a blowing action, generated by a pressure source and transmitted through the permeable wall, causes downwards projection of the batched quantity of product accumulated in the batching chamber, which is then introduced into the underlying container.
The above-described apparatus has been shown to fully satisfy expectations as regards precision of the batching and reliability of functioning: however, during experimentation, some technical-functional aspects have emerged which are not entirely satisfactory.
A first aspect relates to the fact that the cyclic displacement of the obturator towards the advanced position thereof causes an impact to occur, due to encountering of the head of the obturator with the wall of the vertical channel; the noise deriving from this impact can be tolerable where the batching apparatus has one obturator only, or a small number thereof, while it can be excessive in those applications where a battery of obturators is present, working in synchrony on a row of corresponding containers.
A second aspect relates to the development of the path the products is forced to follow from the hopper to the batching chamber, as it is bendy, is subject to passage section narrowing and blind corners, and further the final tract is directed substantially upwards; it follows that filling of the batching chamber is slowed down and therefore the frequency of the operating cycles cannot be very high; further, with very fine powder substance, which does not flow very fast, stagnation of material can occur in some points of the path, due to compacting, with an ensuing need to intensify cleaning interventions.